All publications cited in this application are herein incorporated by reference.
Photosynthetic unicells, such as Chlamydomonas reinhardtii, produce complex and diverse organic compounds from carbon dioxide, inorganic salts, and water by means of photosynthesis. However, unicells are single cells that do not physically attach to other cells under most circumstances.
Multicellular photosynthetic organisms, such as Volvox carteri, have cell walls, also known as extracellular matrices that bind photosynthetic cells together in multicellular photosynthetic organisms. Examples of cell walls include, but are not limited to, the lignified, cellulosic cell walls of plants, the glycoprotein extracellular matrices of many green algae, the siliceous cell walls of diatoms, and the calcareous cell walls of coccolithophorids and coralline red algae. All cell walls have a certain chemical composition that determines their physical properties. The chemical composition of cell walls is determined, in turn, by the specific organic and inorganic molecules secreted from the cells during biological development and by the order in which the various molecules are secreted.
Volvox carteri is a multicellular green alga that exhibits cell-cell adhesion during embryonic development. The adhesion of cells in V. carteri is primarily mediated by glycoproteins, examples of which are designated Algal-CAM, ISG, V1 and V2. These cell adhesion molecules are proteins located on the cell surface involved with the binding with other cells or with the extracellular matrix of the cell. Cell adhesion molecules help cells bind to each other.